Challenges encountered during closure of patent ductus arteriosus.

Transcatheter closure of patent ductus arteriosus (PDA) was one of the first interventions established in invasive cardiology and is now more than 30 years old. The challenges for successful closure with the first devices in children consisted of handling the rather large introducer sheaths and stiff application systems. Today, interventional closure can be performed with different types of plugs, occluders, and coils. Thus, beyond infancy, transcatheter closure can be successfully performed in almost all cases. Challenging from the technical standpoint can be the closure of window-type ducts, in which excessive protrusion of the device into the descending aorta should be avoided, as well as the closure of tubular ducts, in which secure anchoring of one or more devices in the vessel can be very difficult. For the combination of a coarctation and an open duct, different strategies can be considered. In selected cases, use of a covered stent can be helpful. From the physiological standpoint, open ducts in patients with pulmonary hypertension with or without concomitant congenital heart diseases can be challenging because testing of vasoreactivity with temporarily blocked duct and the option of subsequent treatment with vasodilators may be necessary prior to making the decision whether the patient may benefit from definitive duct occlusion or not. Large ducts in infants less than 8 kg can be difficult to treat due to a relative mismatch of introducers, plugs, or occluders to the small anatomic dimensions. The implantation of multiple coils can be associated with a higher risk of device embolization. Unfortunately, for the large group of preterm infants with very low body weights and large ducts of tubular shape there is currently no standardized interventional therapy available.